1. Field of the Invention
The invention relates to a process for preparing hydrogen-containing silanes by disproportionation of a more highly chlorinated silane in the presence of a homogeneous catalyst.
2. Background Art
The demand for the organylhydrogenchlorosilanes MeSiHCl2 and Me2SiHCl is significantly higher than the amount in which they are obtained as by-products in the direct synthesis by the Müller-Rochow process.
EP 286074 A describes a process for the disproportionation of MeSiHCl2 to give MeSiH3 in the presence of a heterogeneous catalyst in a distillation column. In the process, the heterogeneous catalyst has a limited operating life. To replace the catalyst, it is at least necessary to take the portion of the plant charged with the catalyst out of operation in order for the catalyst to be regenerated in the distillation column. Opening of the distillation column and replacement of the catalyst by fresh catalyst is also frequently necessary.
EP 685483 A describes the disproportionation of MeSiHCl2 to give MeSiH3 in the presence of a homogeneous catalyst in a distillation column. However, the poor space-time yield and the high energy consumption stand in the way of the commercialization of the process.
DE 102004045245 A1 describes the disproportionation of HSiCl3 to prepare SiH4 in the presence of a heterogeneous catalyst in a distillation column provided with at least one side reactor. The heterogeneous catalyst is located in the side reactor and can therefore be replaced more simply.